Boiler-furnace



(No Model.)

"J. K. THOMPSON.

BOILER FURNACE.

No. 505,144; Patented Sept. 19, 1893.

UNITED STATES PATENT OFFICE.

JAMES KNAPTON THOMPSON, OF LEEDS, ENGLAND, ASSIGNOR OF TWO- I THIRDS TO CHARLES F. JAHN, OF PITTSBURG, PENNSYLVANIA.

BOILEReFURNACE.

SPECIFICATION forming part of Letters Patent No. 505,144, dated September 19,1893.

Application filed May 31 1893- Serial No. 476,050. (No model.)

To all whom it may concern:

Be it known that I,JAMEs KNAPTON THOMP- SON, a subject of the Queen of GreatBritain, residing at Leeds, in the county of York, England, have invented certain new and useful Improvements in Boiler-Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to furnaces for heating steam boilers and for other purposes,and

, its object is to subject the green fuel to a preliminary combustion or distilling process prior to stoking the same into the fire-box proper of the furnace where the final combustion takes place. By this means, the fuel and the gases, evolved therefrom during the distilling stage, are intimately and thoroughly mixed with air or oxygen, resulting in a perfoot and smokeless combustion, especially when employing a fire-box of the character set forth in my application filed May 2, 1893, Serial No. 472,654.

To carry out this object, my invention, broadly considered, consists in a horizontal gate or fire-bed arranged in the front part of the furnace, upon which the fuel is deposited in a thin layer, in combination with a fire-box arranged in the rear part of the furnace and located at the end of the horizontal fire-bed, the fire-box beingpreferably located below the level of the fire-bed.

My invention also consists in a guard plate preferably adapted to be rocked or swung into various inclinations and arrangedat the juncture of the horizontal firebed and the fire-box, the purpose of this guard plate being to prevent the accidental introduction of green fuel from the fire-bed into the fire-box.

My invention finally consists in such other means, combinationsof parts and features as will be hereinafter set forth and pointed out in the claims.

In the drawingshereunto anneXedFigure 1 represents a vertical longitudinal section of a boiler-furnace embodying my invention in its preferred form, and Fig. 2 is a horizontal section on line 22, Fig. 1. 7

By referring to the drawings, it will be noted that my furnace, in the present instance, is

employed in connection with a large-flue boiler, G, being introduced into one of the 'fiues, 9, thereof.

horizontal fire-bed is constructed in any convenient and suitable manner and, in the present instance, is shown as consisting of the" horizontal grate-bars, a, suitably supported and having an air-chamber, at, below the same. The fire-box, A, is of the character and construction set forth in my application Serial No. 472,654, and consists, briefly considered,

of a downwardly flaring front wall, B, having air-openings along its entire extent, a horizontal bottom grate, O, and arear fire-back, D, continuous and unbroken throughout and extending to within a short distance of the bottom grate, so as to forma throat not only sufficient to permit the free escape of the products of combustion, but to prevent the escape of fuel into the flame-chamber, E, on the other side of the fire-back, preferably in the form of a water-bridge communicating with the body of the boiler, G. A pilot-plate, F, whose functions have been explained in my aforesaid application, is also arranged within thefire-box, and the ash-pit, 0, below the grate, C, is closed air-tight, so as to prevent access of air thereto. Within this ashpit, I preferably arrange a Water-supply, as

set forth in my aforesaid application. A fireback, D, of suitable refractory material, extends upwardly from the bottom of the furnace in the rear of the fire-bridge and serves to properly direct the products of combustion.

Between the horizontal fire-bed, A, and the fire-box, I arrange a guard-plate, H, which, in the present instance, is in the form of an open grating, to permit the passage of air, distilled gases and products of combustion from the fuel on the fire-bed, and this guard plate is preferably pivoted at the upper front edge ofthe fire-box, as shown. The object of this guard-plate is to prevent the accidental discharge, into the fire-box, of the green fuel, before the same has been thoroughly distilled. The rock-shaft, h, of the guard-plate extends out through the side of the boiler, as best shown in Fig. 2, where it is provided with means to raise, or drop, or to adjust the inclination of the said guard-plate. The means preferably consist in two cranks, h, h keyed to the rock-shaft, h, which are connected with two pull-rods, I, 1, extending to the'front of the boiler. The two cranks, h, h are arranged at such an angle that when one crank occupies a position below the dead center and it is desired to raise the guard-plate, the pullrod connected with said crank may be pushed in sufficiently to raise the same over the dead center, so that by pulling the other pull-rod, the guard-plate may be raised to the desired angle, as indicated by full lines in Fig. 1. The pull-rod, I, as indicated, is provided near its forward end with notches, 1', adapted to engage a detent, 7;. By these notches, the

angle of the guard-plate may be suitably varied. The lowermost position of the guardplate is indicated in dotted lines in Fig. 1. Of course, other means for operating theguardplate may be employed, the present device being shown merely as an illustration of such means.

The operation of my furnace is as follows: The fires being started, the green fuel is first stoked in a thin layer upon the horizontal fire-bed, A, through the furnace-door, A and a suitable supply of air being admitted to the air-space, a, the same passes upwardly between the grate-bars, a, to induce the preliminary combustion of distillation of the green fuel. The guard-plate, being in the position indicated in full lines in Fig. 1, prevents any accidental introduction of fuel into the. firebox, A. fuel on the fire-bed having been completed, the same is pushed into the fire-box, A, the guard-plate,H, havin-gbeen first lowered into the position indicated in dotted lines in Fig. 1, by pushing the pull-rod,.I, inwardly. Thereupon, the guard-plate, H, is again raised by cause the crank, h, to clear the dead-c ente-r, and then pulling the pull-rod, I, outwardly until the guard-plate again assumes the position indicated in full lines in Fig. l. A fresh layer of green fuel is then again deposited upon the fire-bed. air-space, a, between theopeningsof the. front wall, B, of the fire-box throughout the entire surface-of the same, produces the necessary down-draft to effect the completecomb-ustion of the fuel, which, by reason of the downwardly flaring shape of the fire-box,. is deposited in loose layers allowing the intimate mixture of the air with the solidfuel, and also; with the hydrocarbons, carbonic oxide and other gases distilled from the fuel onthe fire-bed, which pass into the fire-box in the direction, indicated by the arrows. If any gases should not as readily be-t-aken up by the upper layers of the fuel in the fire-box,as necessary to complete the combustion, the

Theair, passing from the 3 same will pass down the space between the pilot-plate, F, and the fire-bridge, D, and into the incandescent fuel at the bottom of the fire-box. This complete combustion is considerably assisted by the watery-vapors rising from the water-supply in the ash-pan, 0,

below the bottom grate, which also serve to' preserve the said grate against the destructive action of the intense heat of the incandescent fuel resting thereon.

The admission of air to the air-chamber may be efiected in any desired or suitable manner, for example, by providing the door, A with a series of air-openings, of, whose size is controlled by'a damper or register, a,

or in any other suitable way.

I do not herein claim the particular arrangement and construction, per se, of the fire-box, A, and its various parts, inasmuch as the same constitute the subject-matter of the application hereinbefore referred to.

Although I consider the arrangement and construction of parts herein shown and described in illustration of my invention the best way of carrying the same into effect, still it is, manifest that the same may be variously modified, without departing from the spirit of my said invention. I do not, therefore, desire to be confined to the same, but

What I claim, and desire to secure by Letters Patent, is-

1. In a furnace for heating boilers and for other purposes, a front fire-bed,.and a rear fire-box extending below the level of the firebed, in combination with a guard-plate arranged between the fire-bed and the-fire-box, substantially as set forth. The preliminary combustion of the 2. In a furnace for heating boilers and for other purposes, a front fire-bed, and a rear fire-box extending below the l eveiof the firebed, in combination with a pivoted guardplate arranged between the fire-bed and the tire-box, and means for adjusting the angle of the guard-plate, substantially as set forth. first pushing 111 the pull-rod, I, sufficiently to 3. In a furnace for heating boilers and for other purposes, a front firerbed, and a rear f fire-box extending below the level of the fi-rebed, incombination with a perforated guardplate arranged between the fire-bed and the fire-box, substantially as set forth.

at. In a furnace for heating boilers and for other purposes, a horizontal, front fire-bed, in combination with a. fire-box arranged below the level of the fire-bed and comprisinga perforated front wail, a bottom-grate, an airtight chamber below the grate-and a rear, u nbroken fire-bridge extending downwardly from the top of the furnace-chamber to near the bottom-grate, substantially asv set. forth.

5. In a furnace for heating boilers and for other purposes, a horizontal, front fire-bed,

:in combination with a do-wnwardl'yfiaring fire-box arranged below the level of the firebed and comprising a perporated front wall, a bottom-grate, an air-tight chamber below the grate and a rear, unbroken fire-bridge extending downwardly from the top of the furnace-chamber to near the bottom-grate, substantially as set forth.

6. In a furnace for heating boilers and for other purposes, a horizontal, front fire-bed, in combination with a fire-box arranged be low the level of the fire-bed and comprising a perforated front wall, abottom-grate, a rear, unbroken fire-bridge extending downwardly from the top of the furnace-chamber to near the bottom grate, and a pilot-plate arranged within the fire-box, substantially as set forth.

7. A steam boiler, in. combination with a furnace arranged within the flue of the boiler and comprising the followingparts: a horizontal front fire-bed and a rear downwardlyextending fire-box consisting of an open front wall, a bottom grate, an air-tight chamber below the grate and a fire-bridge extending from the top of the furnace-chamber to near 20 the bottom-grate, substantially as set forth.

8. A steam boiler, in combination with a furnace arranged within the flue of the same and comprising the following parts: a hori-. 

